Campbell was eventually carted off with a neck injury and York took to Twitter: “To say I’m disappointed some fans did the wave this afternoon while @Campbell93 was down is understatement. Hope you get well soon Calais.”

This week, the hits kept on coming. The team sent fans “The 49ers Home Field Advantage Plan for Gameday,” which included this cringeworthy tip: “Communication at the line of scrimmage is critical. Keep it quiet when the 49ers are lining up to the ball on offense. Save the noise for the play!”

In advance of his team’s visit to Candlestick on Sunday, Seahawks coach Pete Carroll, who was born in San Francisco and attended Redwood High in Larkspur, was asked for his thoughts on the noise level generated by 49ers fans.

“Um, I think it’s good,” Carroll said. “I’ve been going (to Candlestick) for a long time. It’s always been good. When the fans are fired up, they go for it. It’s got its own way about it. Its own style. It’s classic.

“I feel like I grew up kind of feeling it. I feel real comfortable taking our team in there, but it doesn’t mean their fans aren’t going to go crazy and do everything they can to give their team every advantage. I understand that they’ve already been asking for that.”

It wasn’t clear if Carroll was referring to the “Home Field Advantage Plan” or, perhaps, the imploring of Jim Harbaugh. Today, Harbaugh was asked if he hoped under-construction Levi’s Stadium could eventually provide the type of home-field advantage the Seahawks enjoy at CenturyLink Field.

“I would hope for that (crowd noise) this week,” Harbaugh said. “That Candlestick will get it cranked up. Make it a real great environment because it will be a great football game. I know players will be very enthusiastic for the game. If this doesn’t fire up the fans, then what does?”

Ah, but Harbaugh continued. What could fire up 49ers fans more than a date with the much-loathed Seahawks? Perhaps an impromptu visit from a deceased president?

“I suppose Abraham Lincoln riding across the field with a frock and a top hat, riding a hose, waving an American flag,” Harbaugh said. “I doubt that would fire them up … if this game doesn’t fire them up. The people that really love football (will) be fired up by this matchup.”

We’ll see Sunday. For 49ers fans, it will be a chance to make enough noise to redeem what’s been a forgettable season.